Unfortunately, the only way to be a top notch expert, with mastery over the art or sports, is to start young and with disciplined practice. Does it mean necessarily sacrificing childhood? I am unsure. Michael Jackson comes to mind as he has publicly commented that he didn't have a normal childhood. Jackie Chan also had a hard life as a child, training from a young age but he doesn't seem to resent it as much. However, he doesn't have a good relationship with his kids perhaps because he expected them to go through the same kind of hardship he did (it was normalised for him?)? Russian gymnasts and ballet dancers also train at a very young age.
I guess it's a question many parents struggle with a lot - how much should you push your kids because sometimes it seems kids do waste a lot of time.